1/27/13

After a Cold Week; a Volatile Week Containing Freezing Rain, Possible Thunderstorms, Record Warmth and More Snow!

After a period of rather cold and stable weather; things across Southeast Lower Michigan are about to become very volatile and changeable. The cold Arctic air that's encased the region the past week will be rudely shunted out of the region early in the week. The cold won't leave quietly however; as I look for snow, freezing rain and possible sleet...a mix of precipitation...to overspread the region overnight into Monday morning. Initially; snow accumulations from around an inch to as much as two to four inches will occur across the region...with the highest amounts over the northern and northeast half of the region.

While a light glaze (trace to three tenths of an inch in coldest areas) is likely over much of the region initially; atmospheric conditions are not conducive for a major ice event for a number of reasons. First; the positioning of the Arctic high pressure that feeding the cold air into the region is east southeast of Southeast Michigan over the Mid-Atlantic rather than north or northeast. Second; The surge of the warmer air aloft (and lowering to the surface) will be rather predominant with much of the region climbing above freezing from the wee morning hours to the forenoon hours of Monday from southwest to northeast. Third; It's rather dry aloft and some of the initial precipitation will be "eaten-up" through evaporation. All in all; still not the best of nights to be out and about across Southeast Lower Michigan.

After that initial mess; milder air will infiltrate the region Monday, eating away our snow cover with the warmer air, light rain and drizzle. With the milder air over the frozen ground, this it will be conducive for fog formation. A stronger push of warmer air will give us a prelude to spring Tuesday into Tuesday night as temperatures surge through the 50s to possibly as warm as around 60 at some locations. Keep in mind records for the time period are in the mid to upper 50s.

This spring-like, possible record warmth won't last long however, as a sharp cold front will be approaching the region Wednesday morning. This is liable to touch off some heavy showers and a few thunderstorms as the air becomes marginally unstable. The sharply colder air will spill over the region during Wednesday and changeover any residual moisture to snow. Depending on the changeover time, the intensity of a wave (low pressure) slated to form along the cold front and available moisture, some accumulating snow is possible from the midday to the evening hours of Wednesday.

Stay tuned for updates to this prediction of rather radical changes in the temperatures and weather the next several days. In addition; as things become more certian, I will include more maps for the most notable weather.

Making weather fun while we all learn,Bill Deedler -SEMI_WeatherHistorian